941-22 guruh. Musobaqa #1

Problem Tasks

# Date State
Not Contest

# Date State

D. Sikl6

Time limit : 1000 ms
Memory limit : 64 mb

Berilgan ketma-ketlikni dastlabki $n$ ta xadi yig’indisini toping


$$S = sin(x) - \frac{1}{2} sin(2x) + \frac{1}{3} sin(3x) - \frac{1}{4} sin(4x) + ... + (-1)^{n-1} \frac{1}{n} sin(nx)$$


Kiruvchi ma’lumotlar:

ikkita butun son $n$ va $x$ $(0 \le n,x \le 9)$;


Chiquvchi ma’lumotlar:

$S$ – ketma-ketlikni dastlabki $n$ ta xadi yig’indisi $10^{-3}$ aniqlikda chiqarilsin.

Input
0 1
Output
0.000
Input
2 1
Output
0.387